Can anybody tell me what method they use for tuning high RPM values (ie 2500rpm - 5600rpm)? I'm running a 730 ECM, 8D mask and modified AUJP. I read TRAXION's thread on how to tune part throttle VE with no PE and used that to tune my lower VE table and now I'd like to be able to get some datalogs to nail down my upper VE table. I know that I can move PE up further in the TPS range to keep it from engaging, but problem is, I'm in NYC and tuning this thing on the street, and I'll be at 85mph at 2500rpm before I run into traffic again. Unfortunately I don't have the benefit of a dyno around me either.

Based on engine theory I know my setup will need more fuel in the upper RPMs (AS&M siamesed runners, ported plenum, Super Ram Base and Dyno Don heads) but I can't get into that range without running into something or catching the attention of NYPD. At what point is it acceptable to make an educated guess for your VE values?

Still new to this tuning thing and this board's been really helpful. Thanks for any suggestions.

 

I did mine by using 1st and 2ed gear on the interstate. Just be careful not to blow the engine. Try to limit the high RPM's time to a few seconds at a time. You wouldn't be able to get as very much data but the data you do get will allow you to make an educated guess as to the best settings. For the areas you can't get to, view the table as a 3d graft and just smooth out those areas.

 

Thanks. I've been so used to just throwing it in Drive and going that I forgot we can manually select 1st and 2nd...

I also found an old airfield that's open with a nice LONG runway to do this on. Now, do you do these tests with PE disabled? Or do you just set it to engage with more throttle?

 

Yes. I recommend disabling PE and closed loop. Setting open loop AFR to 13.0:1 or 12.5:1 across the board. Dataloging the WBO2 data, then adjusting the VE until WBO2 reports the correct AFR. I'm not very familiar with your mask so I can't help with all of the specifics needed to accomplish this, but your in the right place.